Effect of cold plasma on proliferation rate of mammalian cells in vitro

Human keratinocytes HaCaT and human carcinoma cells A431 have been treated in vitro by a cold argon plasma jet with an average power value of 0.72 mW/cm2. There were made estimations of proliferation rate and cell viability in a day after the exposition. In contrast to the cell viability of both cell lines there were revealed significant differences in proliferation rates of keratinocytes and cancer cells after plasma treatment.

Investigation of NPB Analogs That Target Phosphorylation of BAD-Ser99 in Human Mammary Carcinoma Cells

The design and development of a small molecule named NPB [3-{(4(2,3-dichlorophenyl)piperazin-1-yl}{2-hydroxyphenyl)methyl}-N-cyclopentylbenzamide], which specifically inhibited the phosphorylation of BAD at Ser99 in human carcinoma cells has been previously reported. Herein, the synthesis, characterization, and effect on cancer cell viability of NPB analogs, and the single-crystal X-ray crystallographic studies of an example compound (4r), which was grown via slow-solvent evaporation technique is reported. Screening for loss of viability in mammary carcinoma cells revealed that compounds such as 2[(4(2,3-dichlorophenyl)piperazin-1-yl][naphthalen-1-yl]methyl)phenol (4e), 5[(4(2,3-dichlorophenyl)piperazin-1-yl][2-hydroxyphenyl)methyl)uran-2-carbaldehyde (4f), 3[(2-hydroxyphenyl][4(p-tolyl)piperazin-1-yl)methyl)benzaldehyde (4i), and NPB inhibited the viability of MCF-7 cells with IC50 values of 5.90, 3.11, 7.68, and 6.5 µM, respectively. The loss of cell viability was enhanced by the NPB analogs synthesized by adding newer rings such as naphthalene and furan-2-carbaldehyde in place of N-cyclopentyl-benzamide of NPB. Furthermore, these compounds decreased Ser99 phosphorylation of hBAD. Additional in silico density functional theory calculations suggested possibilities for other analogs of NPB that may be more suitable for further development.

Synthesis and Cytotoxic Activity of Novel Betulin Derivatives Containing Hydrazide-Hydrazone Moieties

A series of novel betulin derivatives containing hydrazide-hydrazone moieties were synthesized. All compounds were evaluated for their cytotoxicity against four human carcinoma cell lines (HepG2, A549, MCF-7 and HCT-116) and a normal human gastric epithelial cell line (GES-1). Among them, compound 6i was the most potent against HepG2 and MCF-7 cell lines, with IC50 values of 9.27 and 8.87 μM, respectively. The results suggest that the incorporation of a hydrazide-hydrazone side chain at the C-28 position of betulin is beneficial for compounds to display significant cytotoxicity. Compound 6i may be used as a promising skeleton for antitumor agents with improved efficacy.

Precursor-Directed Biosynthesis Mediated Amplification of Minor Aza Phenylpropanoid Piperazines in an Australian Marine Fish-Gut-Derived Fungus, Chrysosporium sp. CMB-F214

Chemical analysis of an M1 agar plate cultivation of a marine fish-gut-derived fungus, Chrysosporium sp. CMB-F214, revealed the known chrysosporazines A–D (11–14) in addition to a suite of very minor aza analogues 1–6. A microbioreactor (MATRIX) cultivation profiling analysis failed to deliver cultivation conditions that significantly improved the yields of 1–6; however, it did reveal that M2 agar cultivation produced the new natural product 15. A precursor-directed biosynthesis strategy adopting supplementation of a CMB-F214 M1 solid agar culture with sodium nicotinate enhanced production of otherwise inaccessible azachrysposorazines A1 (1), A2 (2), B1 (3), C1 (4), C2 (5) and D1 (6), in addition to four new chrysosporazines; chrysosporazines N–P (7–9) and spirochrysosporazine A (10). Structures inclusive of absolute configurations were assigned to 1–15 based on detailed spectroscopic and chemical analyses, and biosynthetic considerations. Non-cytotoxic to human carcinoma cells, azachrysosporazies 1–5 were capable of reversing doxorubicin resistance in P-glycoprotein (P-gp)-overexpressing human colon carcinoma cells (SW620 Ad300), with optimum activity exhibited by the C-2′ substituted analogues 3–5.

De-ubiquitination of SAMHD1 by USP7 overcomes oncogenic stress and contributes to chemotherapy insensitivity

Oncogenic stress induces DNA damage response (DDR) that guards against genetic instability during the evolution of cancer. SAMHD1, a dNTPase protecting cells from viral infections, has been recently found to participate in DNA damage repair process. However, its role in tumorigenesis remains largely unknown. Here, we show that SAMHD1 is up-regulated in early-stage human carcinoma tissues and cell lines under oxidative stress or genotoxic insults. We further demonstrate that de-ubiquitinating enzyme USP7 interacts with SAMHD1 and de-ubiquitinates it at lysine 421, thus stabilizing SAMHD1 protein expression, and promotes tumor cell survival under genotoxic stress. Furthermore, SAMHD1 levels positively correlates with USP7 in various human carcinomas, and is associated with an unfavorable survival outcome in patients who underwent chemotherapy. Moreover, USP7 inhibitor sensitizes tumor cells to chemotherapeutic agents by decreasing SAMHD1 in vitro and in vivo. These findings suggest that targeting USP7 may help overcome chemoresistance, thus necessitating further investigation in the pursuit of precision medicine.

Immunogenicity and Antigenicity of Rabbit Hepatitis E Virus-Like Particles Produced by Recombinant Baculoviruses

Rabbit hepatitis E virus (HEV) is a novel HEV belonging to genotype 3 (HEV-3) in the Orthohepevirus A species of the genus Hepevirus, family Hepeviridae. Rabbit HEV was originally isolated from rabbits and found to cause zoonotic infection. Although rabbit HEV can be successfully grown in culture with several cell lines, including the human carcinoma cell line PLC/PRF/5, it is difficult to obtain the large amounts of viral antigen required for diagnosis and vaccine development. In this study, we expressed N-terminal 13 and 111 aa-truncated rabbit HEV ORF2 proteins using recombinant baculoviruses and obtained two types of virus-like particles (VLPs), RnVLPs and RsVLPs with ~35 and 24 nm diameter, respectively. Anti-rabbit HEV IgG antibodies were induced in high titer by immunizing rabbits with RnVLPs or RsVLPs. The antibody secretion in the serum persisted more than three years. RsVLPs showed stronger antigenic cross-reactivity against HEV-1, HEV-3 and HEV-4 than rat HEV. Moreover, anti-RsVLPs antibodies neutralized not only the cognate virus but also HEV-1, HEV-3 and HEV-4 ex vivo, indicating that rabbit HEV had the same serotype as human HEVs. In contrast, the antibody did not block rat HEV infection, demonstrating that rat HEV belonged to a different serotype. Animal experiments indicated that immunization with either RnVLPs or RsVLPs completely protected the rabbits from challenge by rabbit HEV, suggesting that the VLPs are candidates for rabbit HEV vaccine development.

Biological activity survey of Pereskia aculeata Mill. and Pereskia grandifolia Haw. (Cactaceae)

Background: Pereskia aculeata and P. grandifolia are non-traditional Brazilian vegetables with high nutritional value used in traditional medicine. The antioxidant, anticholinesterase, molluscicidal, cytotoxic, and antiproliferative properties of hydroethanolic extracts of P. aculeata and P. grandifolia leaves (PAL, PGL) and fruits (PAF, PGF) are investigated in this study. Methods: All extracts were prepared by maceration with ethanol 70%. Their antioxidant properties were assessed through DPPH, ABTS, FRAP, and β-carotene bleaching inhibition assays. A TLC bioautography method was employed to evaluate the inhibiting capacity of the acetylcholinesterase enzyme. The molluscicidal activity was tested against the snail Biomphalaria glabrata, which serves as an intermediate host for Schistosoma mansoni. The cytotoxic activity was assessed by a Artemia salina lethality test and the antiproliferative properties against seven human carcinoma cell lines. Results: Compounds with anticholinesterase activity were found in all extracts. Polar compounds present in PAF and PGL extracts were the most active (IC50 < 25 μg of dry mass) and had an adequate inhibition capacity of the AChE. PGF and PGL were classified as moderate (LC50 = 19.2 μg/ml) and modest molluscicidal agents (LC50 = 66.6 μg/ml), respectively. All extracts exhibited selective antiproliferative activity against human chronic myeloid leukemia cell lines (K562). PAL, PGL, and PGF presented potent antiproliferative activity (TGI ≤ 5 μg/ml). Conclusion: Both species exhibited anticholinesterase, cytotoxic and antiproliferative properties. This research supports the potential of these species as sustainable sources of nutraceutical compounds.

Cattleianal and Cattleianone: Two New Meroterpenoids from Psidium cattleianum Leaves and Their Selective Antiproliferative Action against Human Carcinoma Cells

The Myrteacae family is known as a rich source of phloroglucinols, a group of secondary metabolites with notable biological activities. Leaves of Psidium cattleianum were extracted with chloroform: methanol 8:2 to target the isolation of phloroglucinol derivatives. Isolated compounds were characterized using different spectroscopic methods: nuclear magnetic resonance (NMR), ultra-violet (UV) and mass spectrometry (MS). Two new phloroglucinols were evaluated for cytotoxicity against a panel of six human cancer cell lines, namely colorectal adenocarcinoma cells (HT-29 and HCT-116); hepatocellular carcinoma cells (HepG-2); laryngeal carcinoma (Hep-2); breast adenocarcinoma cells (MCF7 and MDA-MB231), in addition to normal human melanocytes HFB-4. Additionally, cell cycle analysis and annexin-V/FITC-staining were used to gain insights into the mechanism of action of the isolated compounds. The new phloroglucinol meroterpenoids, designated cattleianal and cattleianone, showed selective antiproliferative action against HT-29 cells with IC50’s of 35.2 and 32.1 μM, respectively. Results obtained using cell cycle analysis and annexin-V/FITC-staining implicated both necrosis and apoptosis pathways in the selective cytotoxicity of cattleianal and cattleianone. Our findings suggest that both compounds are selective antiproliferative agents and support further mechanistic studies for phloroglucinol meroterpenoids as scaffolds for developing new selective chemotherapeutic agents.